Question
Biradial symmetry and lack of cnidoblasts are the characteristics of [CBSE AIPMT 2006]
(a) Starfish and sea anemone
(b) Ctenoplana and Beroe
(c) Aurelia and Paramecium
(d) Hydra and starfish
Answer/Explanation
Ans. (b)
Ctenoplana and Beroe lack cnidoblasts and have biradial symmetry. These belong to phylum-Ctenophora.
Hydra, sea anemone and Aurelia are coelenterates which have cnidoblasts. Although sea anemone has biradial symmetry.